.container {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 100%;
    height: 100%;
    background-image: url('/common/picture/begin_bg.png');
    background-size: 100% 100%;
}

.btn {
    width: 120px;
    height: 30px;
    font-size: 20px;
    background-color: lightslategrey;
}
